This major cause of chronic suffering is reason enough for a theme issue

Inow begin the journey that will lead me into the sunset of my life,” was how Ronald Reagan described his remaining life.1 That was seven years ago when he told the world that he had Alzheimer's disease. The sunset has been a prolonged one, as is usual in most neurodegenerative disorders, of which Alzheimer's is a prototype. All have an insidious onset, progress slowly over years, and death is usually due to an intercurrent illness and not directly due to the disease itself. Predictably the global burden of diseases like Alzheimer's will rise with increasing longevity. Much of the burden is also borne by carers and relatives. Reagan's daughter, Maureen Reagan, summed up what the illness means to carers. “[Ronald's wife …